Ⅰ、新奧法的設(shè)計(jì)原理
一、隧道設(shè)計(jì)施工的兩大理論及其發(fā)展過(guò)程
二十世紀(jì)以來(lái)，人類(lèi)對(duì)地下空間的需求越來(lái)越多，因而對(duì)地下工程的研究有了一個(gè)突飛猛進(jìn)的發(fā)展。在大量的地下工程實(shí)踐中，人們普遍認(rèn)識(shí)到，隧道及地下洞室工程，其核心問(wèn)題，都?xì)w結(jié)在開(kāi)挖和支護(hù)兩個(gè)關(guān)鍵工序上。即如何開(kāi)挖，才能更有利于洞室的穩(wěn)定和便于支護(hù)：若需支護(hù)時(shí)，又如何支護(hù)才能更有效地保證洞室穩(wěn)定和便于開(kāi)挖。這是隧道及地下工程中兩個(gè)相互促進(jìn)又相互制約的問(wèn)題。
在隧道及地下洞室工程中，圍繞著以上核心問(wèn)題的實(shí)踐和研究，在不同的時(shí)期，人們提出了不同的理論并逐步建立了不同的理論體系，每一種理論體系都包含和解決（或正在研究解決）了從工程認(rèn)識(shí)（概念）、力學(xué)原理，工程措施到施工方法（工藝）等一系列工程問(wèn)題。
一種理論是二十世紀(jì)20年代提出的傳統(tǒng)的“松弛荷載理論”。其核心內(nèi)容是：穩(wěn)定的巖體有自穩(wěn)能力，不產(chǎn)生荷載：不穩(wěn)定的巖體則可能產(chǎn)生坍塌，需要用支護(hù)結(jié)構(gòu)予以支撐。這樣，作用在支護(hù)結(jié)構(gòu)上的荷載就是圍巖在一定范圍內(nèi)由于松弛并可能塌落的巖體重力。這是一種傳統(tǒng)的理論，其代表人物有泰沙基和普氏等人。它類(lèi)似于地面工程考慮問(wèn)題的思想，至今仍被廣泛的應(yīng)用著。
另一種理論是二十世紀(jì)50年代提出的現(xiàn)代支護(hù)理論，或稱(chēng)“巖承理論”。其核心內(nèi)容是：圍巖穩(wěn)定顯然是巖體自身有承載自穩(wěn)能力：不穩(wěn)定圍巖喪失穩(wěn)定是有一個(gè)過(guò)程的，如果在這個(gè)過(guò)程中提供必要的幫助或限制，則圍巖仍然能夠進(jìn)入穩(wěn)定狀態(tài)。這種理論體系的代表性人物有拉布西維茲、米勒-菲切爾、芬納-塔羅勃和卡斯特奈等人。這是一種比較現(xiàn)代的理論，它已經(jīng)脫離了地面工程考慮問(wèn)題的思路，而更接近于地下工程實(shí)際，近半個(gè)世紀(jì)以來(lái)已被廣泛接受和推廣應(yīng)用，并且表現(xiàn)出了廣闊的發(fā)展前景。
由以上可以看出，前一種理論更注意結(jié)果和對(duì)結(jié)果的處理：而后一種理論則更注意過(guò)程和對(duì)過(guò)程的控制，即對(duì)圍巖自承能力的充分利用。由于有此區(qū)別，因

I.The NATM Design Principle
1.Tunnel design and construction of two major theoretical and development process
Since the 20th century, human space on the ground floor of the growing demand, thus the underground works of the study of a rapid development. In a large number of underground engineering practice, it is generally recognized that the tunnel and underground cavern project, the core of the problem, all up in the excavation and retaining two key processes. How excavation, it will be more conducive to the stability and cavern facilitate support : For more support, Supporting how they can more effectively ensure stability and facilitate the cavern excavation. This is the tunnels and underground works two promote each other and check each other's problems.
Tunnels and underground caverns, and focusing on the core issues with the above practice and research, in different periods, People of different theories and gradually established a system of different theories, Each system includes theory and resolve (or are studying the resolution) from the works of understanding (concept), mechanics, engineering measures to the construction methods (Technology), a series of engineering problems.
A theory of the 20th century the 1920s the traditional "load relaxation theory." Its core content is : a stable rock self-stability, no load : unstable rock may have collapsed. need shoring structure to be supported. Thus, the role of the supporting structure of the rock load is within a certain range may be due to relaxation and